Reference may be had to applicant's U.S. Pat. Nos. 3,708,051 and 3,785,031 which show longitudinally movable rods which are rotatable for positively moving pallets into and out of stations through the longitudinal movement of the angularly adjusted rods. In the present arrangement, the shaft is not moved longitudinally and the pallets are raised and lowered from and to the chains at the work station and accurately positioned when the workpiece thereon is being machined as illustrated in said above set forth patents. The pallets are advanced by a pair of chains having friction plates which engage the pallets at the side bottom edges thereof.